Exposure apparatus for forming a reticle

ABSTRACT

A method of forming a reticle includes: loading a blank reticle; projecting an electron beam; moving a second aperture plate having a first pattern aperture and a second pattern aperture so that the first pattern aperture is directly overlapped by a first aperture of a first aperture plate, the electron beam passing through the first pattern aperture after passing the first aperture; exposing the blank reticle with the electron beam after the electron beam passes the first pattern aperture, to form a first exposure pattern; moving the second aperture plate so that the second pattern aperture is directly overlapped by the first aperture of the first aperture plate, the electron beam passing through the second pattern aperture after passing the first aperture; exposing the blank reticle with the electron beam after the electron beam passes the second pattern aperture, to form a second exposure pattern; and developing the blank reticle having the first and second exposure patterns to form the reticle having first and second patterns.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional application based on pending application Ser. No.13/564,195, filed Aug. 1, 2012, the entire contents of which is herebyincorporated by reference.

This application claims priority under 35 USC §119 to Korean PatentApplication No. 10-2011-0085039 filed on Aug. 25, 2011 in the KoreanIntellectual Property Office (KIPO), the entire disclosure of which isincorporated herein by reference.

BACKGROUND

1. Field

Example embodiments relate to an exposure apparatus for forming areticle and a method of forming a reticle using the same.

2. Description of the Related Art

In a photolithography process for forming a semiconductor device, anexposure apparatus may project a pattern of a reticle onto a substrate.The reticle may have various types of patterns, and may be formed bypatterning layers on a quartz plate.

SUMMARY

One or more embodiments may provide a method of forming a reticle,including: loading a blank reticle; projecting an electron beam; movinga second aperture plate having a first pattern aperture and a secondpattern aperture so that the first pattern aperture is directlyoverlapped by a first aperture of a first aperture plate, the electronbeam passing through the first pattern aperture after passing the firstaperture; exposing the blank reticle with the electron beam after theelectron beam passes the first pattern aperture, to form a firstexposure pattern; moving the second aperture plate so that the secondpattern aperture is directly overlapped by the first aperture of thefirst aperture plate, the electron beam passing through the secondpattern aperture after passing the first aperture; exposing the blankreticle with the electron beam after the electron beam passes the secondpattern aperture, to form a second exposure pattern; and developing theblank reticle having the first and second exposure patterns to form thereticle having first and second patterns.

The blank reticle may include a base plate, a blackout film and aphotosensitive film sequentially stacked. Exposing the blank reticle mayinclude exposing the photosensitive film, and developing the blankreticle may include developing the photosensitive film. Developing theblank reticle may include forming first and second masks in thephotosensitive film. The method may further include etching the blackoutfilm using the first and second masks as an etching mask to form thefirst and second patterns.

The second aperture plate may include a plurality of pattern apertures,each of the pattern apertures having different shapes. The secondaperture plate may be moved by rotation. The plurality of second patternapertures may be substantially a same distance from a center of thesecond aperture plate. Each of the first and second exposure patternsmay be formed by one shot.

The method may further include: moving the second aperture plate so thata third aperture in the second aperture plate is directly overlapped bythe first aperture; a portion of the electron beam passing through thethird pattern aperture after passing the first aperture; and exposingthe blank reticle using the electron beam after the electron beam passesthe third pattern aperture, to form a plurality of third exposurepatterns having irregular shapes.

An exposure apparatus may include: an electron gun for projecting anelectron beam; a first aperture plate having a first aperture, the firstaperture being configured to allow at least a portion of the electronbeam to pass therethrough; a second aperture plate having a plurality ofpattern apertures, the second aperture plate being moveable forpositioning any one of the plurality of second apertures in overlappingrelation with the first aperture; a plate holder for supporting thesecond aperture plate; and a driving part for moving the plate holder,the second aperture plate being moved according to the movement of theplate holder. The driving part may rotate the plate holder. The drivingpart may move the plate holder in a straight line. The driving part maymove the plate holder within a plane in which the plate holder lies. Thesecond aperture plate may have one of a circular shape, a ring-typeshape, and a polygonal shape.

One or more embodiments may provide a method of forming a reticle, themethod including: loading a blank reticle; projecting an electron beamtoward the blank reticle; passing a first portion of the electron beamthrough a first aperture plate having a first aperture and a secondaperture plate having a first pattern aperture and a second patternaperture by aligning the first pattern aperture with the first aperture;exposing the blank reticle after the first portion of the electron beampasses the first pattern aperture, to form a first exposure pattern;passing a second portion of the electron beam through the first apertureplate and the second aperture plate by aligning the second patternaperture with the first aperture; exposing the blank reticle after thesecond portion of the electron beam passes the second pattern aperture,to form a second exposure pattern; and developing the blank reticlehaving the first and second exposure patterns to form the reticle havingfirst and second patterns. The second aperture plate may be rectangular.The first pattern aperture and the second pattern aperture are arrangedin a single line. The second aperture plate may be circular. The firstpattern aperture and the second pattern aperture may be arranged in acircle.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of ordinary skill in the art bydescribing in detail exemplary embodiments with reference to theattached drawings in which:

FIG. 1 illustrates an exposure apparatus for forming a reticle inaccordance with example embodiments;

FIG. 2 illustrates a block diagram of a plate holder, a driving motorand a control part included in the exposure apparatus of FIG. 1;

FIGS. 3A to 3D illustrate plan views of a second aperture plate inaccordance with example embodiments;

FIG. 4 illustrates a flow chart of a method of forming a reticle inaccordance with example embodiments;

FIGS. 5 to 7 illustrate perspective views of stages in a method offorming the reticle in accordance with example embodiments;

FIG. 8 illustrates a perspective view of stages in the method of forminga reticle in accordance with example embodiments; and

FIG. 9 illustrates an exposure apparatus for forming the reticle inaccordance with example embodiments;

FIG. 10 illustrates a perspective view of stages in a method of forminga reticle in accordance with example embodiments; and

FIG. 11 illustrates a perspective view of stages in a method of forminga reticle in accordance with example embodiments.

DETAILED DESCRIPTION

Korean Patent Application No. 10-2011-0085039, filed on Aug. 25, 2011,in the Korean Intellectual Property Office (KIPO), and entitled:“Exposure Apparatus for Forming a Reticle and Method of Forming aReticle Using the Same,” is incorporated by reference herein in itsentirety.

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the embodiments to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. Further, it will be understoodthat when a layer is referred to as being “under” another layer, it canbe directly under, and one or more intervening layers may also bepresent. In addition, it will also be understood that when a layer isreferred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent. Also, when an element or layer is referred to as being“connected to” or “coupled to” another element or layer, it can bedirectly connected or coupled to the other element or layer orintervening elements or layers may be present. In contrast, when anelement is referred to as being “directly connected to” or “directlycoupled to” another element or layer, there are no intervening elementsor layers present. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items. Likereference numerals refer to like elements throughout.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present inventive concept.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent inventive concept. As used herein, the singular forms “a,” “an”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It will be further understood thatthe terms “comprises” and/or “comprising,” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments are described herein with reference tocross-sectional illustrations that are schematic illustrations ofidealized example embodiments (and intermediate structures). As such,variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, example embodiments should not be construed as limitedto the particular shapes of regions illustrated herein but are toinclude deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofthe present inventive concept.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concept belongs. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, example embodiments will be described in detail withreference to the accompanying drawings.

FIG. 1 illustrates an exposure apparatus for forming a reticle inaccordance with example embodiments. The reticle may be defined toinclude a blank reticle and patterns thereon.

Referring to FIG. 1, the exposure apparatus may include an electron gun10, an electron beam induction part 29 and a stage 30. The electron gun10 may project an electron beam. The electron beam induction part 29 mayinduce the electron beam projected from the electron beam gun 10 onto asurface of a blank reticle 32. The stage 30 may support the blankreticle 32 thereon.

The electron gun 10 may project an electron beam having a givencross-sectional area. The electron gun 10 may project the electron beamfor a given period. The electron gun 10 may project an electron beamduring a projection period so that an exposure pattern may be formed onthe blank reticle 32.

The electron beam induction part 29 may include a deflector, a pluralityof lenses, aperture plates, a plurality of reflectors, and the like. Theelectron beam induction part 29 may change a shape of an electron beam,control a path of the electron beam, and/or focus the electron beam. Inan example embodiment, the electron beam induction part 29 may include acondenser lens 12, a first aperture plate 14, a projector lens 16, ashaping reflector 18, a second aperture plate 20, a sub-reflector 24, anobjective lens 26, and a main reflector 28.

The condenser lens 12 may focus an electron beam projected from theelectron gun 10.

The first aperture plate 14 may partially block the electron beamfocused by the condenser lens 12 so that a portion of the electron beammay penetrate the first aperture plate 14. A first aperture 14 a of thefirst aperture plate 14 may have a rectangular shape from a plan view.The first aperture 14 a may have a cross-sectional area smaller thanthat of the electron beam focused by the condenser lens 12. Thus, only aportion of the electron beam may penetrate the first aperture plate 14through the first aperture 14 a.

The projector lens 16 and the shaping reflector 18 may control a path ofthe electron beam by deflecting the electron beam.

The second aperture plate 20 may partially block the electron beamhaving penetrated the first aperture plate 14 through the first aperture14 a so that a portion of the electron beam may penetrate the secondaperture plate 20. The second aperture plate 20 may have a plurality ofsecond apertures 22, which may have various shapes from a plan view,e.g., each of the second apertures may have a different shape.Accordingly, the second apertures 22 may include, for example, a firstpattern aperture having a first shape, a second pattern aperture havinga second shape that is different from the first shape, a third patternaperture having a third shape that is different from the first andsecond shapes, and so forth. The second apertures 22 may have anysuitable shape, e.g., circular, ring-type, polygonal shapes, from a planview. In example embodiments, the second apertures 22 may be definedaround a center of the second aperture plate 20, e.g., along acircumferential edge of the second aperture plate 20, and substantiallya same distance from the center of the second aperture plate 20.

FIGS. 3A to 3D illustrate plan views of the second aperture plate 20 inaccordance with example embodiments.

Referring to FIG. 3A, the second aperture plate 20 may have a ring shapeand a flat top surface. The second apertures 22 may be defined along acircumferential edge of the second aperture plate 20, and substantiallya same distance from the center of the second aperture plate 20. Thesecond apertures 22 may form a circular pattern, e.g., may be arrangedin a circle around the center of the second aperture plate 20.

Referring to FIG. 3B, the second aperture plate 20 may have a ring shapeand a flat top surface. The second apertures 22 may form a plurality ofcircular patterns. The second apertures 22 of each circular pattern maybe substantially a same distance from a center of the second apertureplate 20.

Referring to FIG. 3C, the second aperture plate 20 may have arectangular shape and a flat top surface. The second apertures 22 may besubstantially a same distance from a center of the second aperture plate20. The second apertures 22 may form a circular pattern, e.g., may bearranged in a circle.

Referring to FIG. 3D, the second aperture plate 20 may have arectangular shape and a flat top surface. The second apertures 22 mayform a plurality of circular patterns. The second apertures 22 of eachcircular pattern may be substantially a same distance from a center ofthe second aperture plate 20.

A plate holder (not shown) may support the second aperture plate 20. Theplate holder may be connected to a driving part (not shown) to berotated.

FIG. 2 illustrates a block diagram of a plate holder 34, a driving motor36 and a control part 38 included in the exposure apparatus of FIG. 1.

Referring to FIG. 2, the plate holder 34 may be connected to the drivingmotor 36 that may be connected to a control part 38. The plate holder 34may be rotated by the driving motor 36. As the plate holder 34 rotates,the second aperture plate 20, supported by the plate holder 34, may alsorotate.

When the second aperture plate 20 rotates, at least one of the secondapertures 22 may directly overlap the first aperture 14 a. The secondaperture plate 20 may be rotated so that at least one of the secondapertures 22 may directly overlap the first aperture 14 a. As such, theelectron beam, having penetrated the first aperture 14 a, may beincident upon at least one of the second apertures 22 without changing abeam axis thereof. Accordingly, the beam may not have an aberration sothat it may be regularly incident upon the blank reticle 32, e.g.,without deflection of the beam. The electron beam incident on the blankreticle 32 may have a regular profile. As such, a beam calibration inthe exposure process may not be needed or a period for the beamcalibration may be lengthened. Thus, a process time for exposure on theblank reticle 32 may be shortened.

As mentioned above, the second apertures 22 may have various shapes. Forexample, each of the second apertures 22 may have a different shape. Thesecond aperture plate 20 may be rotated so that the first aperture 14 adirectly overlaps any one of the second apertures 22. Accordingly, aspecific exposure pattern may be formed by one exposure using the secondapertures 22.

The sub-reflector 24 and the main reflector 28 may control a path of theelectron beam having passed by the second aperture 22. The electron beammay be focused a final time by the objective lens 26. After the finalfocus of the electron beam, the electron beam may be projected on theblank reticle 32 supported by the stage 30.

According to example embodiments, semiconductor circuit patterns havingvarious shapes may be formed on the blank reticle 32 by projecting anelectron beam using the exposure apparatus. Additionally, unlike avariable shaped beam (VSB) generally having one rectangular shapedaperture, the exposure apparatus may select various shaped secondapertures 22 so that more complex patterns may be formed on the blankreticle 32 by one shot, e.g., one exposure. Thus, an exposure patternthat may be formed by several shots using the VSB exposure apparatus maybe formed by one shot using the exposure apparatus in accordance withexample embodiments.

FIG. 4 illustrates a flow chart of a method of forming a reticle inaccordance with example embodiments. FIGS. 5 to 7 illustrate perspectiveviews of stages in the method of forming the reticle in accordance withexample embodiments.

The reticle formed herein may include a first region in which aplurality of regular patterns may be formed and a second region in whicha plurality irregular patterns may be formed. For example, the regularpatterns may be patterns for forming memory cells, and the irregularpatterns may be patterns for forming peripheral circuit patterns.According to one or more embodiments, the first region may have firstand second patterns repeatedly arranged therein, and the second regionmay have third patterns therein.

Referring to FIGS. 1 and 4, a blackout film (not shown) may be formed ona base plate including quartz. The blackout film may include, e.g.,chromium. A photosensitive film (not shown) may be further formed on theblackout film. A structure including the base plate, the blackout filmand the photosensitive film sequentially stacked may be defined as ablank reticle 32.

In step S10, the blank reticle 32 may be loaded onto the stage 30 of theexposure apparatus.

Referring to FIG. 5 and step S12 in FIG. 4, the second aperture plate 20may be moved so that the first aperture 14 a may directly overlap asecond aperture 22 a for a first pattern (first pattern aperture),without changing a beam axis of an electron beam that has passed thefirst aperture 14 a. The electron beam having passed the first aperture14 a may not be deflected to penetrate the second aperture 22 a for thefirst pattern. As such, the second aperture plate 20 having the secondaperture 22 a for the first pattern may be moved so that the electronbeam may penetrate the second aperture 22 a for first pattern with nochange of the beam axis thereof.

The movement of the second aperture plate 20 may be, e.g., a rotation, afirst-dimensional movement, e.g., one directional movement, or asecond-dimensional movement, e.g., two directional movement, and thelike. In the present embodiment, the second aperture plate 20 mayrotate.

For example, the second aperture plate 20 may be rotated so that thesecond aperture 22 a for the first pattern may be placed at a positionby which an electron beam having penetrating the first aperture 14 a maypass with no change of the beam axis of the electron beam. The electronbeam having passed through the second aperture 22 a for the firstpattern may be projected onto the blackout film of the blank reticle 32.

In step S14, the blank reticle 32 may be moved in a horizontal directionand the electron beam may be repeatedly projected to various positionsof the blank reticle 32 via the first aperture 14 a and the secondaperture 22 a for the first pattern. Thus, a plurality of first exposurepatterns 40 a may be formed in the first region of the blank reticle 32.

Referring to FIG. 6 and step 16 in FIG. 4, after forming the firstexposure patterns 40 a, the second aperture plate 20 may be rotated sothat a second aperture 22 b for a second pattern (second patternaperture) may be placed at a position through which an electron beamhaving penetrated the first aperture 14 a may pass, with no change ofthe beam axis of the electron beam in step S16.

In step S18, the blank reticle 32 may be moved in a horizontal directionand the electron beam may be repeatedly projected to various positionsof the blank reticle 32 via the first aperture 14 a and the secondaperture 22 b for the second pattern. Thus, a plurality of secondexposure patterns 40 b may be formed in the first region of the blankreticle 32.

By the above processes, regular patterns may be formed in the firstregion of the blank reticle 32. Shapes of the regular patterns may bedifferent from each other according to process steps for manufacturing asemiconductor device, and one or more of the second apertures 22 may beselected to be used for forming patterns.

Referring to FIG. 7 and step S20 in FIG. 4, the second aperture plate 20may be rotated so that a second aperture 22 c for a third pattern (thirdpattern aperture), may be placed at a position by which an electron beamhaving penetrated the first aperture 14 a may pass with no change of thebeam axis of the electron beam. The third pattern aperture may have arectangular shape. In step S22, the blank reticle 32 may be moved in ahorizontal direction and the electron beam may be repeatedly projectedto various positions of the blank reticle 32 via the first aperture 14 aand the second aperture 22 c for the third pattern. Thus, a plurality ofthird exposure patterns 40 c may be formed in the second region of theblank reticle 32.

In step S24, the photosensitive film of the blank reticle 32 may bedeveloped to form first, second and third masks.

The blackout film may be etched using the masks as an etching mask toform the first, second and third patterns for forming circuit. Thus, thereticle, including the patterns on the base plate, may be formed.

As illustrated above, various patterns for the reticle may be achievedby selecting various ones of the second apertures 22. Thus, the amountof exposing and the time for exposing may be reduced. Additionally, thebeam axis may not be changed so that the aberration of the electron beammay not occur.

FIG. 8 illustrates a perspective view of stages in a method of forming areticle in accordance with example embodiments.

The method may be substantially the same as the method illustrated withreference to FIGS. 1 to 7, except that an electron beam having passedthe first aperture may be deflected to be incident a second apertureplate.

Referring to FIG. 8, a second aperture plate 20 may include the secondapertures 22, which form a first circular pattern, and second apertures22 a for a first pattern, which form a second circular pattern, e.g.,within the first circular pattern. The second aperture plate 20 may berotated to allow an electron beam that has penetrated a first aperture14 a to pass through the second aperture 22 a. Unlike the secondapertures 22, which may be rotated to directly overlap the firstaperture 14 a, the second apertures 22 a may not directly overlap thefirst aperture 14 a. Thus, after passing the first aperture 14 a, theelectron beam may be deflected, e.g., a beam axis of the electron beammay be changed, to pass through the second apertures 22 a. However, adegree, e.g., an angle, of the change may not be so great to cause aquality of the electron beam to be degenerated. If, instead, one of thesecond apertures 22 is selected for the electron beam to pass throughafter passing the first aperture 12 a, no change of the beam axis mayresult.

A plurality of first exposure patterns 40 a may be formed in a firstregion of the blank reticle 32 after the electron beam passes the firstaperture 14 a and the second aperture 22 a for the first pattern.

The second aperture plate 20 may be rotated so that a second aperture(not shown) for a second pattern may be positioned such that an electronbeam having penetrated the first aperture 14 a may pass through thesecond aperture 22 a. By a method substantially the same as that used togenerate the first exposure patterns 40 a, a plurality of secondexposure patterns (not shown) may be formed in a second region of theblank reticle 32.

The second aperture plate 20 may be rotated so that a third aperture(not shown) for a third pattern may be positioned such that an electronbeam having penetrated the first aperture 14 a may pass through thethird aperture. By a method substantially the same as that used togenerate the first exposure patterns 40 a, a plurality of secondexposure patterns (not shown) having irregular shapes may be formed in athird region of the blank reticle 32.

A photosensitive film (not shown) of the blank reticle 32 may bedeveloped to form first, second and third masks. A blackout film (notshown) may be etched using the masks as an etching mask to form thefirst, second and third patterns for forming circuit. Thus, the reticleincluding the patterns on the base plate may be formed.

As discussed above, even though the beam axis may be changed, thequality of the electron beam may not be degenerated because the changeof the beam axis may not be so great.

FIG. 9 illustrates an exposure apparatus for forming a reticle inaccordance with example embodiments.

The exposure apparatus may be substantially the same as that of FIG. 1,except that a second aperture plate may be moved in a straight line,instead of rotated, and that the second aperture plate may have arectangular shape in which second apertures may be arranged in astraight line.

Referring to FIG. 9, a second aperture plate 50 may have various typesof second apertures 52. The second apertures 52 may be arranged in anysuitable manner, e.g., in a straight line. The second apertures 52 maybe arranged in a single line or in a plurality of lines.

A plate holder (not shown) may support the second aperture plate 50, andmay be connected to a driving motor (not shown) and a control part (notshown). The driving motor may drive the plate holder in a straight line.

The plate holder may drive the second aperture plate 50 so that one ofthe second apertures 52 may directly overlap a first aperture 14 a.Thus, the electron beam may pass the first aperture 14 a and one of thesecond apertures 52 with no change of the beam axis thereof.

FIG. 10 illustrates a perspective view of stages in a method of forminga reticle in accordance with example embodiments.

The method may be substantially the same as that of FIGS. 1 to 7, exceptthat a second aperture plate may move in a straight line.

Referring to FIG. 10, the second aperture plate 50 may be moved in astraight line so that a second aperture 52 a may directly overlap afirst aperture 14 a. A blank reticle 32 may be exposed by the electronbeam that passes the first aperture 14 a and the second aperture 52 a.The blank reticle 32 may be moved so that a plurality of exposurepatterns 40 a may be formed in the blank reticle 32, e.g., in differentpositions of the blank reticle 32.

The exposure process may be repeatedly performed to form a plurality ofsecond exposure patterns (not shown), and further to form a plurality ofthird exposure patterns (not shown) having irregular shapes. In exampleembodiments, the beam axis may be changed slightly so that the qualityof the beam may not be degenerated. After the exposure process, adeveloping process and etching process may be performed to form thereticle having patterns therein.

FIG. 11 illustrates a perspective view of stages in a method of forminga reticle in accordance with example embodiments.

The method may be substantially the same as that of FIGS. 1 to 7, exceptthat a second aperture plate may move in a plane, e.g., within a planein which the second aperture plate lies.

Referring to FIG. 11, a second aperture plate 50 may be moved in a planeso that a second aperture 52 a may directly overlap a first aperture 14a. A blank reticle 32 may be exposed by the electron beam that passesthe first aperture 14 a and the second aperture 52 a. The blank reticle32 may be moved so that a plurality of exposure patterns 40 a may beformed in the blank reticle 32, e.g., in different positions of theblank reticle.

The exposure process may be repeatedly performed to form a plurality ofsecond exposure patterns (not shown), and further to form a plurality ofthird exposure patterns (not shown) having irregular shapes. In exampleembodiments, the beam axis may be changed slightly so that the qualityof the beam may not be degenerated. After the exposure process, adeveloping process and etching process may be performed to form thereticle having patterns therein.

The exposure apparatus for forming a reticle, according to theembodiments, may have high efficiency for forming the reticle. One ormore embodiments may provide a method of forming a reticle using theexposure apparatus for forming the reticle. According to exampleembodiments, when forming various types of patterns using an exposureapparatus, an electron beam may not be deflected by moving a secondaperture plate. Additionally, various types of apertures in the secondaperture plate may be used for forming various types of patterns. Thus,the amount and time of exposure may be reduced.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

1.-10. (canceled)
 11. An exposure apparatus, comprising: an electron gunfor projecting an electron beam; a first aperture plate having a firstaperture, the first aperture being configured to allow at least aportion of the electron beam to pass therethrough; a second apertureplate having a plurality of pattern apertures, the second aperture platebeing moveable for positioning any one of the plurality of patternapertures in overlapping relation with the first aperture; a plateholder for supporting the second aperture plate; and a driving part formoving the plate holder, the second aperture plate being moved accordingto the movement of the plate holder.
 12. The exposure apparatus asclaimed in claim 11, wherein the driving part rotates the plate holder.13. The exposure apparatus as claimed in claim 11, wherein the drivingpart moves the plate holder in a straight line.
 14. The exposureapparatus as claimed in claim 11, wherein the driving part moves theplate holder within a plane in which the plate holder lies.
 15. Theexposure apparatus as claimed in claim 11, wherein the second apertureplate has one of a circular shape, a ring-type shape, and a polygonalshape. 16.-20. (canceled)